Samsung Air Conditioner Error Code E406

E406 indicates that the COND OUT 1 sensor on the outdoor unit has broken away or become disconnected from its proper position. This is the condenser outlet temperature sensor, which the system uses to monitor refrigerant temperature leaving the condenser coil. Without a valid reading from this sensor, the unit shuts down to prevent unsafe operation. The fault is often resolved by physically reattaching and securing the sensor rather than replacing it.

No. The system has disabled itself because it cannot monitor condenser outlet temperature, which is a key protection parameter for the compressor and refrigerant circuit. Attempting to bypass or ignore this fault and force the unit to run could lead to compressor damage or further system failures. The error should be resolved before returning the unit to normal operation.

A power reset alone is unlikely to permanently clear E406 because the fault is caused by a physical disconnection of the sensor, not a software or communication glitch. The unit may temporarily restart but will likely re-trigger the fault once it attempts to read the missing sensor signal. The sensor must be physically reattached and secured before the error will stay cleared.

If the sensor has simply come loose from its mounting clip or the connector has pulled free, a knowledgeable DIYer can inspect the outdoor unit, reseat the sensor against the condenser coil, and firmly reconnect the wiring harness. However, if the wiring is damaged or the sensor itself has failed, those repairs may require a certified HVAC technician, particularly because accessing the outdoor control board and refrigerant-side components involves working with live electrical systems.

If the sensor only needs to be repositioned and secured, the repair cost is primarily a service call fee, which typically ranges from $75 to $150 depending on location. If the sensor itself is damaged and must be replaced, parts and labor combined can range from $100 to $300. Control board replacement, if the connector port is damaged, would increase costs further.